JPH05115861A - Construction method for environmental maintenance - Google Patents

Abstract

PURPOSE:To surely prevent cotaminants from spilling outside a contaminated area and to increase its reliability. CONSTITUTION:In a construction method where an isolation wall is built around an area which is contaminated or likely to be contaminated to prevent contaminants from moving from the area to the surrounding, a hollow holding body 13 having plural through hole 13a communicating with both the inside and outside is embedded in a excavated ditch 11 which have been excavated previously and simultaneously a contaminant capturing material 18 is filled inside the hollow holding body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an environmental conservation construction method,
Especially around the contaminated or suspected areas,
The present invention relates to an environmental protection method for preventing the influence on the environment by constructing a barrier wall that blocks the movement of pollutants from the area to the surroundings.

[0002]

2. Description of the Related Art With the development of industry and diversification of urban life, the problems of industrial waste and municipal waste have been greatly highlighted. In particular, in addition to an increase in the amount of waste treated, it is a serious problem that harmful substances contained in the waste, for example, heavy metals such as mercury, cadmium, and chromium, flow out into the living area, for example, through groundwater.

To this end, the preferred solution is to construct a barrier around the contaminated or suspected contaminated area, which blocks the migration of contaminants from the area to the surroundings. In fact, it has been practiced in the past to construct concrete walls around that area, or even concrete impermeable walls at the bottom.

However, a concrete wall has a high possibility of penetrating heavy metals, and if cracks occur, they will intensively flow out from there.

On the other hand, Japanese Patent Laid-Open No. 61-105500 proposes to inject a material having a high barrier property against heavy metals into cracks in the barrier wall.

[0006]

However, as far as the investigation is made only from the blockage of heavy metals and the like, it is not possible to deal with cracks caused by external factors such as earthquakes or aging.

[0007] Therefore, the main object of the present invention is to provide an excellent pollutant blocking or trapping property.

[0008]

SUMMARY OF THE INVENTION The above-mentioned problem is solved in advance by a method of constructing a barrier wall around a contaminated or suspected contaminated area to prevent the migration of contaminants from the area to the periphery. The problem can be solved by embedding a hollow holder having a plurality of through holes communicating with the inside and the outside in the excavated trench and arranging the pollutant trapping substance therein.

In addition, a hollow holder having a plurality of through holes communicating with the inside and the outside is embedded in a previously excavated trench, and a space forming body is inserted into these hollow holders to enter the liquid hollow holder. In the state where the invasion of the hollow holding body and the excavation groove is prevented, the space forming body is removed from the hollow holding body, and then the contaminants in the removed space are removed. A capture substance can be provided. In this case, a plurality of hollow holders can be arranged in parallel in the direction of the excavation groove, and a hollow or solid space forming body can be inserted into the hollow holder at the same time as or after the insertion of the hollow holders. Furthermore, at the same time when the hollow holder is inserted, or before the solidification of the solidifying material is started, a flexible bag is inserted into the hollow holder to set the bag inside the hollow holder before the solidification of the solidifying material is started. Inflate and maintain the expanded state until at least the fluidity of the solidified material disappears,
After that, the bag body can be contracted and removed from the hollow holding body. On the other hand, by embedding a hollow holder having no through holes in the excavated groove that was previously excavated, the solidification between the hollow holder and the excavated groove was achieved by a solidifying material, and then from the inside of the hollow holder to its wall. A plurality of holes may be perforated, and a substance for trapping the contaminant may be provided in the hollow holder.

Further, a hollow holder having a plurality of through holes in a previously excavated trench and the through holes being sealed with a sealing material is embedded, and a hollow holder is provided between the hollow holder and the trench. It is also possible to achieve solidification with a solidifying material and then break or remove the sealing material from the inside of the hollow holder to provide a substance for trapping the pollutant in the hollow holder.

Further, the trapping substance is filled in a cassette holder having a large number of through holes of a size that does not allow the trapping substance to pass through,
The cassette can be loaded into the hollow holder at least after the fluidity of the solidified material has been lost.

[0012]

According to the present invention, a hollow holder having a plurality of through holes communicating with the inside and outside is buried in a previously excavated trench, and a trapping substance for the pollutant is provided therein. Therefore, when the contaminant enters the hollow holder through the through hole, it can be captured by the trapping substance inside and prevented from flowing further. As described above, in the present invention, the blocking of pollutants does not rely on the liquid-tightness of the material, but is made from the viewpoint of capturing and blocking the pollutants,
Therefore, even if a crack occurs in the barrier wall,
Since it can be prevented from flowing out to the surroundings, it becomes highly reliable.

Further, by relying only on the trapping effect of the pollutant, if the trapping substance exists in the barrier wall, the barrier wall is mainly used to block the pollutant, and if it passes through cracks, etc. When the substance is trapped by the trapping substance, a double blocking effect is exhibited, and the blocking reliability is increased.
Therefore, it is desirable to fill the space between the excavation groove and the hollow holder with a solidifying material. In this case, by inserting the space forming body in the hollow holder, it is possible to prevent the liquid from entering the hollow holder. After that, after solidifying with a solidifying material between the hollow holding body and the excavation groove, if the space forming body is removed from the hollow holding body, a space can be formed at the removed place, and a contaminant can be formed in this space. A capture substance can be provided.

On the other hand, when the hollow holder is made to have a long excavation groove, one hollow holder can be provided for each excavation groove, for example, a thin rectangular box body. Even if a plurality of them are arranged side by side at intervals, the liquid containing the contaminant that has entered the blocking wall easily penetrates into the hollow holding body when there is a pressure difference between the hollow holding body and the wall body, The pollutant is captured. Therefore, the material cost is lower and the construction method is simpler than the case of constructing a continuous wall of the trapping substance.

The space forming body may be solid or hollow. In addition, the space forming body may be inserted at the same time as or after the hollow holder is inserted.

Further, in the case of forming the space forming body, a flexible bag body is inserted into the hollow holding body at the same time as the hollow holding body is inserted or after the solidifying material is started to solidify. Before the solidification is started, the bag body is inflated by injecting air or liquid, for example, to be inflated, and the expanded state is maintained until at least the fluidity of the solidified material disappears, and then the bag body is contracted to hollow body. Can be removed from. When this bag is used, the bag can be well adhered to the hollow holder and the solidified material can be surely prevented from entering the hollow holder, and the removal work can be performed very easily.

On the other hand, the hollow holder may not have a through hole. In this case, after the hollow holder is buried, solidification is made between the hollow holder and the excavation groove by a solidifying material. Then, if a plurality of holes are formed in the wall of the hollow holder from the inside, contaminants can be introduced into the inside. Another similar method is to embed a hollow holder having a plurality of through holes in a previously excavated trench and the through holes being sealed with, for example, a heat-melting or breakable sealing material. Then, the space between the hollow holder and the excavation groove is solidified by the solidifying material, and then the sealing material is broken or removed from the inside of the hollow holder by heating with a gas torch, etc. It is also possible to provide a substance trapping substance.

[0018]

The present invention will be described in more detail below. FIG. 1 is a conceptual diagram of a construction target area of the present invention, which is an example of constructing a blocking wall 2 surrounding a waste disposal site. Around the contaminated or suspected contaminated area, the barrier wall 2 for preventing the migration of pollutants from the area to the periphery is preferably provided with an impermeable layer 3 in the lower part thereof. Reach impermeable layer 3 to build. In addition, if the impermeable layer 3 is not provided or if there is a risk of infiltration of groundwater downward, a bottom wall similar to the blocking wall can be constructed below the contaminated region by appropriate means. The bottom wall is preferably continuous with the blocking wall 2. If necessary, the blocking wall 2
Alternatively, the liquid-impermeable sheets 5A and 5B can be arranged inside the bottom wall.

Now, the first in the case of constructing the blocking wall 2
Examples of are shown in FIGS. That is, first, as shown in FIG. 2, the guide wall 10 is constructed and the long excavation groove 11 is excavated. When excavating while using the stabilizing liquid 12 such as bentonite during this excavation, the hole wall becomes stable. Then, as shown in FIG.
A hollow holder having a, for example, a hollow pipe 13 is formed in the excavation groove 1
Insert in 1. In this case, as shown in FIG. 8, the hollow pipes 13 are arranged in the excavation groove 11 at intervals so that the capturing piles 4, 4, ... Are finally arranged side by side in the longitudinal direction of the excavation groove 11. insert. Further, when the spacer 14 for steadying is fixed around the hollow tube 13 and inserted, the centering is easy. The spacer 14 can be removed later or buried in it.

Then, as shown in FIG. 4, a hollow space forming tube 15 with a bottom is inserted into the hollow tube 13. in this case,
The space forming pipe 15 may be inserted into the excavation groove 11 together with the hollow pipe 13. The space forming tube 15 is preferably provided with a bottom so that the stabilizing solution 12 does not enter from the bottom. Instead of the space forming tube 15, a solid tube may be used.

When the insertion of the space forming tube 15 is completed,
As shown in FIG. 5, the solidifying material 16 is solidified by adding a hardening additive to the stabilizing solution 12 and stirring it to cure it, or by replacing the stabilizing solution 12 with cement, for example.

After the solidifying material 16 loses its fluidity or solidifies, as shown in FIG. 6, the space forming tube 15 is formed.
Is drawn out, and the drawn-out space is used as a filling space 17. Then, as shown in FIG. 7, the trapping substance 18 for pollutants is put into the hollow tube 13 to fill it.

In the above example, the hollow tube 13 and the space forming tube 15 may be a metal tube or a plastic tube such as vinyl chloride. In order to facilitate the removal of the space forming tube 15, an oil-based mold release agent may be applied to the inner surface of the hollow tube 13 or the outer surface of the space forming tube 15, or both of them. Sand or the like may be poured between them.

In the present invention, the trapping substance adsorbs or retains pollutants, for example, activated carbon, zeolite, vermiculite, kaolin, sodium bentonite, silica, blast furnace slag, and other clay minerals alone or in combination. Can be used in the state.
This type of compound can be used because it has an ion exchange capacity and an adsorption capacity. In addition, one or more of the materials disclosed in the above publications can be mixed and used. When the pollutant is ammonia nitrogen or the like, a trapping substance corresponding to these can be used. There may be many types of pollutants in the waste dump. Therefore, the types of the trapping substances used in the trapping piles 4, 4, ... Can be made different. The trapping substance may be unit particles as they are, but may be used in the form of aggregates or agglomerates such as pellets. Furthermore, the surface of the capture substance can be coated with another capture substance, in particular a material which dissolves over time in contact with a liquid.

FIG. 9 shows another embodiment, which is shown in FIG.
As shown in FIG. 3, the excavation groove 11 is previously excavated to have a plurality of through holes 20a therein, and the through holes 20a are sealing materials 21, for example, a sealing material that is melted by heat such as rubber or plastic. A hollow holding body sealed by 21, for example, a hollow holding pipe 20 is embedded, solidification is performed by the solidifying material 16 between the hollow holding body and the excavation groove 11, and the solidifying material 16 loses fluidization. At a later point in time, a sealing material melting means, for example, a gas torch 22 is lowered into the hollow holding tube 20, and hot gas is blown to the sealing material 21 at the location of the sealing material 21 to melt the sealing material 21. Let through 20
Open a. After performing this for all the through holes 20a, 20a ..., The trapping substance 18 is filled in the hollow holding tube 20. In this case, the sealing material 21 can be mechanically broken by, for example, a drill.

Further, a bag may be provided on the entire inner surface of the hollow holding tube 20 and used as a sealing material for the through holes 20a.

On the other hand, when the holding pipe 20 is a plastic pipe such as vinyl chloride, it is not necessary to form a through hole in advance and to seal it with a sealing material, and the holding pipe 20 is built in the excavation groove 11. After the solidifying material is solidified, the holding tube 20 can be forcibly formed with a through hole by a drill or the like.

FIGS. 10 to 12 show still another embodiment, in which the hollow holding tube 13 having a plurality of through holes 13a is inserted at the same time or after that, before the solidification of the solidifying material 16 is started. A flexible bag body 30 made of rubber or plastic is inserted into the holding tube 13, and the bag body 30 is filled with a gas such as air or a liquid such as water before the solidifying material 16 is solidified. It is pressure-fed through and injected, and inflated in the hollow holding tube 13 to maintain the expanded state until at least the fluidity of the solidifying material 16 disappears, after which the fluid in the bag body 30 is drained to remove the bag body 30. It can be contracted and removed from the hollow retainer.

FIG. 13 shows an embodiment in which the aspect is further different, and a through hole 40a having a size that does not permeate the trapping substance.
A cassette holder 40 having a large number of holes, for example, a trapezoid having a large number of holes formed in a rectangular box, is filled with the trapping substance 18, and the cassette 41 is filled with a panel-like hollow at least after the fluidity of the solidifying material is lost. Holder 1
It can be loaded into 3A. The cassette 41 can be made detachable by providing a suspension ring 42 or the like. As shown in FIG. 14, a mesh basket may be used as the cassette holder 40A.

In this case, the eye forming the through hole is required to be smaller than the trapping substance. In any case, when the hollow holder has a cylindrical shape or a rectangular tube shape, the cassette can be adapted to the sectional shape. Furthermore, when the holder is a hollow tubular one, as shown in FIG.
A cylindrical cassette 41A can be used, and one long holding tube or a plurality of short holding tubes can be continuously inserted into one hollow holding tube.

When such a cassette 41 or 41A is used, it is convenient to replace it when the trapping ability of the trapping substance decreases or disappears. When the cassette is not used, the trapping substance in the hollow holder can be scraped out and replaced by an appropriate means.

By the way, as shown in FIG. 16, in order to enhance the property of blocking contaminants, the hollow holding pipe 13 and the excavation groove 11 are provided.
A pollutant blocking film 50 may be provided between the sinking bar 51 and the solidifying material 16. In this case, the sinking bar 51 or the like may be used as a weight in order to enhance the sinkability against the buoyancy of the solidifying material 16 or the buoyancy of the stabilizing liquid. You can

[0033]

As described above, according to the present invention, it is possible to reliably prevent the contaminants from flowing out of the contaminated region, and there are advantages such as high reliability.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state in which a barrier wall is constructed according to the present invention.

FIG. 2 is a schematic sectional view of a first step of a construction example of the first example of the present invention.

FIG. 3 is a schematic sectional view of a second step of the construction example of the first example of the present invention.

FIG. 4 is a schematic sectional view of a third step of the construction example of the first example of the present invention.

FIG. 5 is a schematic sectional view of a fourth step of the construction example of the first example of the present invention.

FIG. 6 is a schematic sectional view of a fifth step of the construction example of the first example of the present invention.

FIG. 7 is a schematic sectional view of a sixth step of the construction example of the first example of the present invention.

FIG. 8 is a horizontal cross-sectional view of the blocking wall showing a completed construction state of the first example of the present invention.

FIG. 9 is a cross-sectional view of another example of the present invention.

FIG. 10 is a schematic sectional view showing an example of a construction process of another example of the present invention.

FIG. 11 is a schematic cross-sectional view showing the next step of the construction process of another example of the present invention.

FIG. 12 is a schematic cross-sectional view showing still another step of the construction process of another example of the present invention.

FIG. 13 is a perspective view showing a state where a cassette according to the present invention is inserted.

FIG. 14 is a perspective view showing an example of another cassette according to the present invention.

FIG. 15 is a perspective view showing the insertion state of another cassette according to the present invention.

FIG. 16 is a cross-sectional view of an installation example of a barrier film according to the present invention.

[Explanation of symbols]

1 ... Waste, 2 ... Barrier wall, 3 ... Impermeable layer, 4 ... Supplementary pile,
5A, 5B ... Liquid-impermeable sheet, 11 ... Drilling groove, 12 ... Stabilizing liquid, 13 ... Hollow holder, 13a ... Through hole, 14 ... Spacer, 15 ... Space forming tube, 16 ... Solidifying material, 17 ... Space , 18 ... supplementary substance, 20 ... hollow holding tube, 21 ... sealing material, 22 ... gas torch, 30 ... bag, 41, 41A ... cassette, 50 ... barrier membrane.

Claims (8)

[Claims] 1. A method of constructing a barrier wall around a contaminated or suspected contaminated area to prevent the migration of pollutants from the area to the surroundings, wherein the inside and outside of a pre-excavated excavation groove. An environmental protection method characterized in that a hollow holder having a plurality of through holes communicating with is embedded and a trapping substance for the pollutant is provided therein. 2. A hollow holder having a plurality of through holes communicating with the inside and the outside is buried in a previously excavated excavation groove, and a space forming body is inserted into these hollow holders to enter a liquid hollow holder. In the state where the invasion of the hollow holding body and the excavation groove is prevented, the space forming body is removed from the hollow holding body, and then the contaminants in the removed space are removed. An environmental protection method characterized by providing a trapping substance. 3. A plurality of hollow holders are arranged side by side at intervals in the direction of the excavation groove, and a hollow or solid space forming body is inserted into the hollow holder at the same time as or after the insertion of the hollow holders. Environmental protection construction method described in 2. 4. A flexible bag body is inserted into the hollow holder at the same time as the hollow holder is inserted or after the solidification of the solidifying material is started, and the bag body is hollowed before the solidification of the solidifying material is started. 3. The environmental protection method according to claim 2, wherein the hollow body is inflated to maintain the expanded state at least until the solidified material loses fluidity, and then the bag body is contracted and removed from the hollow body. 5. A method for constructing a barrier wall around a contaminated or suspected contaminated area to prevent the migration of pollutants from the area to the surroundings, wherein a penetration wall is provided in a previously excavated trench. A hollow holder having no holes is buried, and a solidifying material is used to solidify between the hollow holder and the excavation groove, and then a plurality of holes are bored from the inside of the hollow holder to its wall. The environmental protection method according to claim 1, wherein a trapping substance for the pollutant is provided. 6. A method for constructing a barrier wall around a contaminated or suspected contaminated area to prevent the migration of pollutants from the area to the surroundings, wherein a plurality of holes are provided in a previously excavated trench. Of the hollow holder is buried by embedding a hollow holder whose through hole is sealed by a sealing material, and the hollow holder and the excavation groove are solidified by a solidifying material, and then the hollow holder An environmental protection method characterized in that a sealing material is broken or removed from the inside and a trapping substance for the pollutant is provided in the hollow holder. 7. The environmental protection method according to claim 1, wherein a trapping substance whose trapping ability is reduced or lost is replaced. 8. A trapping substance is filled in a cassette holder having a large number of through holes having a size that does not allow the trapping substance to pass therethrough, and the cassette is mounted in the hollow holder at least after the fluidity of the solidified material is lost. The environmental protection construction method according to claim 1, which is included.